The present invention generally relates to a rail grinding apparatus. More particularly, the present invention relates to an easily transportable rail grinding apparatus.
Railroad tracks are subject to wear by the passage of trains over the rails. In particular, depressions in the upper surface of a rail may develop such that the rail head presents an undulating, corrugated surface. The rail may also develop burrs, or otherwise lose its symmetrical profile.
Maintaining a smooth running surface is important for a variety of reasons including safety, riding comfort, protection of the track, track bed and rolling stock, noise suppression, and reduced maintenance of the track and track bed.
It is known to use grinding machines for maintaining railroad track rails in smooth, properly shaped condition. Examples of two such rail grinding machines are disclosed in U.S. Pat. Nos. 4,829,723 and 4,862,647, both of which are assigned to the assignee of the present application.
Such grinding machines generally include a plurality of rotatable grinding modules that are carried by a locomotive or the like in close proximity to the rail head surfaces of a railroad track. The grinding modules include rotatable, abrasive grinding stones that can be lowered into a position flush with the rail surface to grind and restore the rail surface to a smooth, desired profile.
The grinding modules include replaceable, abrasive grinding stones that are rotated about a grinding axis. The grinding stones preferably have a generally flat, annular grinding surface, which is located perpendicular to the axis of rotation of the grinding stones. While the grinding surface of the grinding stone is worn by the grinding process, the grinding surface can be maintained essentially flat and perpendicular to the grinding axis by grinding only on an inner diameter of the grinding stone. Using this process, the grinding surface is placed on the rail so that the rail sides do not extend beyond the inner diameter of the grinding stone.
It can be preferable in some situations to have the grinding marks left by the grinding stone on the rail head be perpendicular to a longitudinal axis of the rail. Such perpendicular grinding marks are left when the grinding is done on the inner diameter of the grinding stone. More precisely, perpendicular grinding marks are left on the rail head when the line of contact between the grinding stone and the rail head is along a diameteral line of the grinding stone, perpendicular to and intersecting the grinding axis of rotation.
Another consideration when grinding rails to a desired profile is the presence of obstructions to the grinding stone. For example at road crossings, where the track intersects a street, wooden ties or rubber guards are typically mounted in close proximity of the track to allow for smooth passage of wheeled vehicles across the track rails. Tilting of the grinding modules to shape the profile of the rail head can bring the grinding stones into interfering contact with the wooden ties or rubber guards.
Another portion of railroad tracks that poses a particularly challenge to maintain in a smooth condition is switches where different set of tracks come together. Undulations in the rail surfaces can impart vibratory motion to rolling stock that will continue long after the train has passed to switch. However, the converging nature of the rails at switches presents a barrier to the use of most conventional rail grinding machines.
Jaeggi, U.S. Pat. No. 5,525,098 discloses a rail grinding apparatus that includes a transport vehicle that is capable of moving on rails and conventional roads. The rail grinding apparatus also includes a rail grinder that is towed behind the transport vehicle. The transport vehicle includes a lift mechanism that lifts the rail grinder off the rails to facilitate transporting the rail grinder to a location where the rail grinder is to be used.
The present invention relates to a rail grinding apparatus for use in grinding rails. The rail grinding apparatus includes a transport vehicle and a rail grinding unit. The transport vehicle is capable of moving along the rails or a conventional road. The rail grinding unit is capable of grinding at least one of the rails. The rail grinding unit is movable between a stored position on the transport vehicle and a deployed position on the rails.
The present invention also relates to a method of grind rails. The method includes providing a transport vehicle that is capable of moving along rails and a conventional road. A rail grinding unit is placed in a stored position on the transport vehicle. The rail grinding unit is moved from the stored position to a deployed position on the rails. At least one of the rails is grinded with the rail grinding unit.